Long-term survival and center volume for functionally single-ventricle congenital heart disease in England and Wales.

OBJECTIVES: Long-term survival is an important metric for health care evaluation, especially in functionally single-ventricle (f-SV) congenital heart disease (CHD). This study's aim was to evaluate the relationship between center volume and long-term survival in f-SV CHD within the centralized health care service of England and Wales. METHODS: This was a retrospective cohort study of children born with f-SV CHD between 2000 and 2018, using the national CHD procedure registry, with survival ascertained in 2020. RESULTS: Of 56,039 patients, 3293 (5.9%) had f-SV CHD. Median age at first intervention was 7 days (interquartile range [IQR], 4, 27), and median follow-up time was 7.6 years (IQR, 1.0, 13.3). The largest diagnostic subcategories were hypoplastic left heart syndrome, 1276 (38.8%); tricuspid atresia, 440 (13.4%); and double-inlet left ventricle, 322 (9.8%). The survival rate at 1 year and 5 years was 76.8% (95% confidence interval [CI], 75.3%-78.2%) and 72.1% (95% CI, 70.6%-73.7%), respectively. The unadjusted hazard ratio for each 5 additional patients with f-SV starting treatment per center per year was 1.04 (95% CI, 1.02-1.06), P < .001. However, after adjustment for significant risk factors (diagnostic subcategory; antenatal diagnosis; younger age, low weight, acquired comorbidity, increased severity of illness at first procedure), the hazard ratio for f-SV center volume was 1.01 (95% CI, 0.99-1.04) P = .28. There was strong evidence that patients with more complex f-SV (hypoplastic left heart syndrome, Norwood pathway) were treated at centers with greater f-SV case volume (P < .001). CONCLUSIONS: After adjustment for case mix, there was no evidence that f-SV center volume was linked to longer-term survival in the centralized health service provided by the 10 children's cardiac centers in England and Wales.

Linkage of National Congenital Heart Disease Audit data to hospital, critical care and mortality national data sets to enable research focused on quality improvement.

OBJECTIVES: To link five national data sets (three registries, two administrative) and create longitudinal healthcare trajectories for patients with congenital heart disease (CHD), describing the quality and the summary statistics of the linked data set. DESIGN: Bespoke linkage of record-level patient identifiers across five national data sets. Generation of spells of care defined as periods of time-overlapping events across the data sets. SETTING: National Congenital Heart Disease Audit (NCHDA) procedures in public (National Health Service; NHS) hospitals in England and Wales, paediatric and adult intensive care data sets (Paediatric Intensive Care Audit Network; PICANet and the Case Mix Programme from the Intensive Care National Audit & Research Centre; ICNARC-CMP), administrative hospital episodes (hospital episode statistics; HES inpatient, outpatient, accident and emergency; A&E) and mortality registry data. PARTICIPANTS: Patients with any CHD procedure recorded in NCHDA between April 2000 and March 2017 from public hospitals. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary: number of linked records, number of unique patients and number of generated spells of care. Secondary: quality and completeness of linkage. RESULTS: There were 143 862 records in NCHDA relating to 96 041 unique patients. We identified 65 797 linked PICANet patient admissions, 4664 linked ICNARC-CMP admissions and over 6 million linked HES episodes of care (1.1M inpatient, 4.7M outpatient). The linked data set had 4 908 153 spells of care after quality checks, with a median (IQR) of 3.4 (1.8-6.3) spells per patient-year. Where linkage was feasible (in terms of year and centre), 95.6% surgical procedure records were linked to a corresponding HES record, 93.9% paediatric (cardiac) surgery procedure records to a corresponding PICANet admission and 76.8% adult surgery procedure records to a corresponding ICNARC-CMP record. CONCLUSIONS: We successfully linked four national data sets to the core data set of all CHD procedures performed between 2000 and 2017. This will enable a much richer analysis of longitudinal patient journeys and outcomes. We hope that our detailed description of the linkage process will be useful to others looking to link national data sets to address important research priorities.

Cohort study of intervened functionally univentricular heart in England and Wales (2000-2018).

OBJECTIVE: Given the paucity of long-term outcome data for complex congenital heart disease (CHD), we aimed to describe the treatment pathways and survival for patients who started interventions for functionally univentricular heart (FUH) conditions, excluding hypoplastic left heart syndrome. METHODS: We performed a retrospective cohort study using all procedure records from the National Congenital Heart Diseases Audit for children born in 2000-2018. The primary outcome was mortality, ascertained from the Office for National Statistics in 2020. RESULTS: Of 53 615 patients, 1557 had FUH: 55.9% were boys and 67.4% were of White ethnic groups. The largest diagnostic categories were tricuspid atresia (28.9%), double inlet left ventricle (21.0%) and unbalanced atrioventricular septal defect (AVSD) (15.2%). The ages at staged surgery were: initial palliation 11.5 (IQR 5.5-43.5) days, cavopulmonary shunt 9.2 (IQR 6.0-17.1) months and Fontan 56.2 (IQR 45.5-70.3) months. The median follow-up time was 10.8 (IQR 7.0-14.9) years and the 1, 5 and 10-year survival rates after initial palliation were 83.6% (95% CI 81.7% to 85.4%), 79.4% (95% CI 77.3% to 81.4%) and 77.2% (95% CI 75.0% to 79.2%), respectively. Higher hazards were present for unbalanced AVSD HR 2.75 (95% CI 1.82 to 4.17), atrial isomerism HR 1.75 (95% CI 1.14 to 2.70) and low weight HR 1.65 (95% CI 1.13 to 2.41), critical illness HR 2.30 (95% CI 1.67 to 3.18) or acquired comorbidities HR 2.71 (95% CI 1.82 to 4.04) at initial palliation. CONCLUSION: Although treatment pathways for FUH are complex and variable, nearly 8 out of 10 children survived to 10 years. Longer-term analyses of outcome based on diagnosis (rather than procedure) can inform parents, patients and clinicians, driving practice improvements for complex CHD.

Ethnic-specific mortality of infants undergoing congenital heart surgery in England and Wales.

PURPOSE: To investigate ethnic differences in mortality for infants with congenital heart defects (CHDs) undergoing cardiac surgery or interventional catheterisation. DESIGN: Observational study of survival to age 1 year using linked records from routine national paediatric cardiac surgery and intensive care audits. Mortality risk was investigated using multivariable Poisson models with multiple imputation. Predictors included sex, ethnicity, preterm birth, deprivation, comorbidities, prenatal diagnosis, age and weight at surgery, preprocedure deterioration and cardiac diagnosis. SETTING: All paediatric cardiac surgery centres in England and Wales. PATIENTS: 5350 infants with CHDs born from 2006 to 2009. MAIN OUTCOME MEASURE: Survival at age 1 year. RESULTS: Mortality was 83.9 (95% CI 76.3 to 92.1) per 1000 infants, with variation by ethnic group. Compared with those of white ethnicity, infants in British Asian (Indian, Pakistani and Bangladeshi) and 'all other' (Chinese, mixed and other) categories experienced significantly higher mortality by age 1 year (relative risk [RR] 1.52[95% CI 1.19 to 1.95]; 1.62[95% CI 1.20 to 2.20], respectively), specifically during index hospital admission (RR 1.55 [95% CI 1.07 to 2.26]; 1.64 [95% CI 1.05 to 2.57], respectively). Further predictors of mortality included non-cardiac comorbidities, prenatal diagnosis, older age at surgery, preprocedure deterioration and cardiac diagnosis. British Asian infants had higher mortality risk during elective hospital readmission (RR 1.86 [95% CI 1.02 to 3.39]). CONCLUSIONS: Infants of British Asian and 'all other' non-white ethnicity experienced higher postoperative mortality risk, which was only partly explained by socioeconomic deprivation and access to care. Further investigation of case-mix and timing of risk may provide important insights into potential mechanisms underlying ethnic disparities.

Mixed-methods evaluation of the Perioperative Medicine Service for High-Risk Patients Implementation Pilot (POMSHIP): a study protocol.

INTRODUCTION: Perioperative complications have a lasting effect on health-related quality of life and long-term survival. The Royal College of Anaesthetists has proposed the development of perioperative medicine (POM) services as an intervention aimed at improving postoperative outcome, by providing better coordinated care for high-risk patients. The Perioperative Medicine Service for High-risk Patients Implementation Pilot was developed to determine if a specialist POM service is able to reduce postoperative morbidity, failure to rescue, mortality and cost associated with hospital admission. The service involves individualised objective risk assessment, admission to a postoperative critical care unit and follow-up on the surgical ward by the POM team. This paper introduces the service and how it will be evaluated. METHODS AND ANALYSIS OF THE EVALUATION: A mixed-methods evaluation is exploring the impact of the service. Clinical effectiveness of the service is being analysed using a 'before and after' comparison of the primary outcome (the PostOperative Morbidity Score). Secondary outcomes will include length of stay, validated surveys to explore quality of life (EQ-5D) and quality of recovery (Quality of Recovery-15 Score). The impact on costs is being analysed using 'before and after' data from the Patient-Level Information and Costing System and the National Schedule of Reference Costs. The perceptions and experiences of staff and patients with the service, and how it is being implemented, are being explored by a qualitative process evaluation. ETHICS AND DISSEMINATION: The study was classified as a service evaluation. Participant information sheets and consent forms have been developed for the interviews and approvals required for the use of the validated surveys were obtained. The findings of the evaluation are being used formatively, to make changes in the service throughout implementation. The findings will also be used to inform the potential roll-out of the service to other sites.

Parents' Experiences of Caring for Their Child at the Time of Discharge After Cardiac Surgery and During the Postdischarge Period: Qualitative Study Using an Online Forum.

BACKGROUND: Congenital heart disease (CHD) is the most common class of birth defects, which encompasses a broad spectrum of severity ranging from relatively minor to extremely complex. Improvements in surgery and intensive care have resulted in an increasing number of infants with the most complex lesions surviving after surgery until the time of discharge from the hospital, but there remain concerns about out-of-hospital mortality, variability in how services are provided at the time of discharge and beyond, and difficulties experienced by some families in accessing care. OBJECTIVE: As part of a mixed-methods program of research, this study aimed to elicit parental experiences of caring for a child with CHD after hospital discharge following a cardiac surgery and collect information to inform interviews for a subsequent stage of the project. METHODS: A closed online discussion group was set up via the main Facebook page of the Children's Heart Federation (CHF), a national charity offering support to children with heart disease and their families. The discussion group was advertised through the charity's webpage, and interested participants were directed to the charity's Facebook page from where they could access the closed Facebook group and respond to questions posted. The CHF moderated the forum, and the research team provided questions to be posted on the forum. Responses were collated into a single transcript and subjected to thematic analysis. RESULTS: The forum was open for 4 months, and 91 participants (mean age 35 years, range 23-58 years, 89 females, 89 parents, and 2 grandparents) submitted demographic information and were given access to the closed forum group. A common experience of isolation emerged from the data, with descriptions of how that isolation was experienced (physical, social, knowledge) and its psychological impact, together with the factors that made it worse or better. Woven through this theme was the notion that parents developed expertise over time. CONCLUSIONS: The use of an online forum provided a means for eliciting data from a large number of parents regarding their experiences of caring for their child after hospital discharge following cardiac surgery. Parents engaged with the forum and were able to articulate what went well and what went less well, together with sharing their stories and supporting each other through doing so. Some parents clearly found participating in the forum a positive experience in itself, demonstrating the potential of social media as a mechanism for providing support and reducing isolation. Information gained from the forum was used to shape questions for interviews with parents in a subsequent phase of the study. Furthermore, the themes identified in the online forum have contributed to identifying ways of improving the provision of care and support for parents of high-risk babies following discharge after cardiac surgery.

Issues facing families of infants discharged after cardiac surgery: the perceptions of charity helpline staff.

AIM: To elicit the perceptions of helpline staff who talk to parents of children discharged after cardiac surgery in infancy about parents' key concerns. METHODS: A qualitative study involving semistructured interviews with 10 staff at four heart charities. Interviews were recorded, transcribed and analysed using Framework analysis. RESULTS: Staff identified the knowledge, communication and support needs of parents which they described in terms of the impact of patient and family factors, sources of support and systems. Staff perceptions of helplines, in terms of the function of a helpline and the roles of its staff, together with staff's personal views based on their experience of multiple encounters with many families, influenced how they viewed families' needs and responded to their requests. CONCLUSION: Helpline staff provided important, previously uncaptured evidence about the challenges faced by parents of children discharged after cardiac surgery in infancy. Staff have an important role in supporting communication, in terms of speaking to families about how to talk to professionals and talking to professionals directly to get or give information when parents are unable to do so. Capturing the perspective of helpline staff about communication issues has highlighted the need for interventions with professionals as well as parents.

Improving Risk Adjustment for Mortality After Pediatric Cardiac Surgery: The UK PRAiS2 Model.

BACKGROUND: Partial Risk Adjustment in Surgery (PRAiS), a risk model for 30-day mortality after children's heart surgery, has been used by the UK National Congenital Heart Disease Audit to report expected risk-adjusted survival since 2013. This study aimed to improve the model by incorporating additional comorbidity and diagnostic information. METHODS: The model development dataset was all procedures performed between 2009 and 2014 in all UK and Ireland congenital cardiac centers. The outcome measure was death within each 30-day surgical episode. Model development followed an iterative process of clinical discussion and development and assessment of models using logistic regression under 25 × 5 cross-validation. Performance was measured using Akaike information criterion, the area under the receiver-operating characteristic curve (AUC), and calibration. The final model was assessed in an external 2014 to 2015 validation dataset. RESULTS: The development dataset comprised 21,838 30-day surgical episodes, with 539 deaths (mortality, 2.5%). The validation dataset comprised 4,207 episodes, with 97 deaths (mortality, 2.3%). The updated risk model included 15 procedural, 11 diagnostic, and 4 comorbidity groupings, and nonlinear functions of age and weight. Performance under cross-validation was: median AUC of 0.83 (range, 0.82 to 0.83), median calibration slope and intercept of 0.92 (range, 0.64 to 1.25) and -0.23 (range, -1.08 to 0.85) respectively. In the validation dataset, the AUC was 0.86 (95% confidence interval [CI], 0.82 to 0.89), and the calibration slope and intercept were 1.01 (95% CI, 0.83 to 1.18) and 0.11 (95% CI, -0.45 to 0.67), respectively, showing excellent performance. CONCLUSIONS: A more sophisticated PRAiS2 risk model for UK use was developed with additional comorbidity and diagnostic information, alongside age and weight as nonlinear variables.

Incorporating Comorbidity Within Risk Adjustment for UK Pediatric Cardiac Surgery.

BACKGROUND: When considering early survival rates after pediatric cardiac surgery it is essential to adjust for risk linked to case complexity. An important but previously less well understood component of case mix complexity is comorbidity. METHODS: The National Congenital Heart Disease Audit data representing all pediatric cardiac surgery procedures undertaken in the United Kingdom and Ireland between 2009 and 2014 was used to develop and test groupings for comorbidity and additional non-procedure-based risk factors within a risk adjustment model for 30-day mortality. A mixture of expert consensus based opinion and empiric statistical analyses were used to define and test the new comorbidity groups. RESULTS: The study dataset consisted of 21,838 pediatric cardiac surgical procedure episodes in 18,834 patients with 539 deaths (raw 30-day mortality rate, 2.5%). In addition to surgical procedure type, primary cardiac diagnosis, univentricular status, age, weight, procedure type (bypass, nonbypass, or hybrid), and era, the new risk factor groups of non-Down congenital anomalies, acquired comorbidities, increased severity of illness indicators (eg, preoperative mechanical ventilation or circulatory support) and additional cardiac risk factors (eg, heart muscle conditions and raised pulmonary arterial pressure) all independently increased the risk of operative mortality. CONCLUSIONS: In an era of low mortality rates across a wide range of operations, non-procedure-based risk factors form a vital element of risk adjustment and their presence leads to wide variations in the predicted risk of a given operation.

"I was so worried about every drop of milk" - feeding problems at home are a significant concern for parents after major heart surgery in infancy.

Increasing numbers of operations in small infants with complex congenital heart disease are being carried out in the UK year on year, with more surviving the initial operation. However, even after successful surgery some of these infants remain fragile when they are discharged home. The aim of the study was to elicit parents' experiences of caring for a child with complex needs after major congenital heart surgery. We conducted a qualitative study involving semi-structured interviews with parents of 20 children (aged <1-5 months at hospital discharge), who had undergone open heart surgery and subsequently died or been readmitted unexpectedly to intensive care following their initial discharge home. Feeding difficulties following discharge from the specialist surgical centre emerged as one of the most significant parental concerns spontaneously raised in interviews. For some parents the impact of feeding difficulties overshadowed any other cardiac concerns. Key themes centred around feeding management (particularly the practical challenges of feeding their baby), the emotional impact of feeding for parents and the support parents received or needed after discharge with respect to feeding. Caring for a child with congenital heart disease following surgery is demanding, with feeding difficulties being one of the most significant parent stressors. Local health professionals can be a good source of support for parents provided that they are well informed about the needs of a cardiac baby and have realistic expectations of weight gain. Specialist surgical centres should consider addressing issues of parental stress around feeding and weight gain prior to hospital discharge. © 2016 Blackwell Publishing Ltd.

Death and Emergency Readmission of Infants Discharged After Interventions for Congenital Heart Disease: A National Study of 7643 Infants to Inform Service Improvement.

BACKGROUND: Improvements in hospital-based care have reduced early mortality in congenital heart disease. Later adverse outcomes may be reducible by focusing on care at or after discharge. We aimed to identify risk factors for such events within 1 year of discharge after intervention in infancy and, separately, to identify subgroups that might benefit from different forms of intervention. METHODS AND RESULTS: Cardiac procedures performed in infants between 2005 and 2010 in England and Wales from the UK National Congenital Heart Disease Audit were linked to intensive care records. Among 7976 infants, 333 (4.2%) died before discharge. Of 7643 infants discharged alive, 246 (3.2%) died outside the hospital or after an unplanned readmission to intensive care (risk factors were age, weight-for-age, cardiac procedure, cardiac diagnosis, congenital anomaly, preprocedural clinical deterioration, prematurity, ethnicity, and duration of initial admission; c-statistic 0.78 [0.75-0.82]). Of the 7643, 514 (6.7%) died outside the hospital or had an unplanned intensive care readmission (same risk factors but with neurodevelopmental condition and acquired cardiac diagnosis and without preprocedural deterioration; c-statistic 0.78 [0.75-0.80]). Classification and regression tree analysis were used to identify 6 subgroups stratified by the level (3-24%) and nature of risk for death outside the hospital or unplanned intensive care readmission based on neurodevelopmental condition, cardiac diagnosis, congenital anomaly, and duration of initial admission. An additional 115 patients died after planned intensive care admission (typically following elective surgery). CONCLUSIONS: Adverse outcomes in the year after discharge are of similar magnitude to in-hospital mortality, warrant service improvements, and are not confined to diagnostic groups currently targeted with enhanced monitoring.

Going home after infant cardiac surgery: a UK qualitative study.

OBJECTIVE: To qualitatively assess the discharge processes and postdischarge care in the community for infants discharged after congenital heart interventions in the first year of life. DESIGN: Qualitative study using semistructured interviews and Framework Analysis. SETTING: UK specialist cardiac centres and the services their patients are discharged to. SUBJECTS: Twenty-five cardiologists and nurses from tertiary centres, 11 primary and secondary health professionals and 20 parents of children who had either died after discharge or had needed emergency readmission. RESULTS: Participants indicated that going home with an infant after cardiac intervention represents a major challenge for parents and professionals. Although there were reported examples of good care, difficulties are exacerbated by inconsistent pathways and potential loss of information between the multiple teams involved. Written documentation from tertiary centres frequently lacks crucial contact information and contains too many specialist terms. Non-tertiary professionals and parents may not hold the information required to respond appropriately when an infant deteriorates, this contributing to the stressful experience of managing these infants at home. Where they exist, the content of formal 'home monitoring pathways' varies nationally, and families can find this onerous. CONCLUSIONS: Service improvements are needed for infants going home after cardiac intervention in the UK, focusing especially on enhancing mechanisms for effective transfer of information outside the tertiary centre and processes to assist with monitoring and triage of vulnerable infants in the community by primary and secondary care professionals. At present there is no routine audit for this stage of the patient journey.

Signs of deterioration in infants discharged home following congenital heart surgery in the first year of life: a qualitative study.

AIMS: To describe the ways in which parents recognise and make decisions about their child's symptoms following discharge home after congenital heart interventions in the first year of life and their experiences of seeking help. METHODS: This was a qualitative study involving semistructured interviews with parents. Twenty-one parents were recruited to the study. Parents all had a child who had congenital heart surgery in their first year of life between September 2009 and October 2013 at one of three UK cardiac centres; the children had either died or were readmitted as an emergency following initial discharge. RESULTS: Some parents were unable to identify any early warning signs. Others described symptoms of deterioration including changes in feeding and appearance, respiratory distress and subtle behavioural changes that may not be routinely highlighted to parents at discharge. Several barriers to accessing prompt medical assistance were identified including parents feeling that their concerns were not taken seriously, long wait times and lack of protocols at A&E. CONCLUSIONS: Our study highlights behavioural symptoms as being a potentially underemphasised sign of deterioration and identifies a number of barriers to parents accessing support when they are concerned. It is important that parents are encouraged to seek advice at the earliest opportunity and that those health professionals at the front line have access to the information they need in order to respond in an appropriate and timely way. A role for home monitoring was also noted as potentially useful in identifying at risk children who appear clinically well.

Trends in 30-day mortality rate and case mix for paediatric cardiac surgery in the UK between 2000 and 2010.

OBJECTIVES: To explore changes over time in the 30-day mortality rate for paediatric cardiac surgery and to understand the role of attendant changes in the case mix. METHODS SETTING AND PARTICIPANTS: Included were: all mandatory submissions to the National Institute of Cardiovascular Outcomes Research (NICOR) relating to UK cardiac surgery in patients aged <16 years. The χ(2) test for trend was used to retrospectively analyse the proportion of surgical episodes ending in 30-day mortality and with various case mix indicators, in 10 consecutive time periods, from 2000 to 2010. Comparisons were made between two 5-year eras of: 30-day mortality, period prevalence and mean age for 30 groups of specific operations. MAIN OUTCOME MEASURE: 30-day mortality for an episode of surgical management. RESULTS: Our analysis includes 36 641 surgical episodes with an increase from 2283 episodes in 2000 to 3939 in 2009 (p<0.01). The raw national 30-day mortality rate fell over the period of review from 4.3% (95% CI 3.5% to 5.1%) in 2000 to 2.6% (95% CI 2.2% to 3.0%) in 2009/2010 (p<0.01). The case mix became more complex in terms of the percentage of patients <2.5 kg (p=0.05), with functionally univentricular hearts (p<0.01) and higher risk diagnoses (p<0.01). In the later time era, there was significant improvement in 30-day mortality for arterial switch with ventricular septal defect (VSD) repair, patent ductus arteriosus ligation, Fontan-type operation, tetralogy of Fallot and VSD repair, and the mean age of patients fell for a range of operations performed in infancy. CONCLUSIONS: The raw 30-day mortality rate for paediatric cardiac surgery fell over a decade despite a rise in the national case mix complexity, and compares well with international benchmarks. Definitive repair is now more likely at a younger age for selected infants with congenital heart defects.

Real time monitoring of risk-adjusted paediatric cardiac surgery outcomes using variable life-adjusted display: implementation in three UK centres.

OBJECTIVE: To implement routine in-house monitoring of risk-adjusted 30-day mortality following paediatric cardiac surgery. DESIGN: Collaborative monitoring software development and implementation in three specialist centres. PATIENTS AND METHODS: Analyses incorporated 2 years of data routinely audited by the National Institute of Cardiac Outcomes Research (NICOR). Exclusion criteria were patients over 16 or undergoing non-cardiac or only catheter procedures. We applied the partial risk adjustment in surgery (PRAiS) risk model for death within 30 days following surgery and generated variable life-adjusted display (VLAD) charts for each centre. These were shared with each clinical team and feedback was sought. RESULTS: Participating centres were Great Ormond Street Hospital, Evelina Children's Hospital and The Royal Hospital for Sick Children in Glasgow. Data captured all procedures performed between 1 January 2010 and 31 December 2011. This incorporated 2490 30-day episodes of care, 66 of which were associated with a death within 30 days.The VLAD charts generated for each centre displayed trends in outcomes benchmarked to recent national outcomes. All centres ended the 2-year period within four deaths from what would be expected. The VLAD charts were shared in multidisciplinary meetings and clinical teams reported that they were a useful addition to existing quality assurance initiatives. Each centre is continuing to use the prototype software to monitor their in-house surgical outcomes. CONCLUSIONS: Timely and routine monitoring of risk-adjusted mortality following paediatric cardiac surgery is feasible. Close liaison with hospital data managers as well as clinicians was crucial to the success of the project.

Development of a diagnosis- and procedure-based risk model for 30-day outcome after pediatric cardiac surgery.

OBJECTIVE: The study objective was to develop a risk model incorporating diagnostic information to adjust for case-mix severity during routine monitoring of outcomes for pediatric cardiac surgery. METHODS: Data from the Central Cardiac Audit Database for all pediatric cardiac surgery procedures performed in the United Kingdom between 2000 and 2010 were included: 70% for model development and 30% for validation. Units of analysis were 30-day episodes after the first surgical procedure. We used logistic regression for 30-day mortality. Risk factors considered included procedural information based on Central Cardiac Audit Database "specific procedures," diagnostic information defined by 24 "primary" cardiac diagnoses and "univentricular" status, and other patient characteristics. RESULTS: Of the 27,140 30-day episodes in the development set, 25,613 were survivals, 834 were deaths, and 693 were of unknown status (mortality, 3.2%). The risk model includes procedure, cardiac diagnosis, univentricular status, age band (neonate, infant, child), continuous age, continuous weight, presence of non-Down syndrome comorbidity, bypass, and year of operation 2007 or later (because of decreasing mortality). A risk score was calculated for 95% of cases in the validation set (weight missing in 5%). The model discriminated well; the C-index for validation set was 0.77 (0.81 for post-2007 data). Removal of all but procedural information gave a reduced C-index of 0.72. The model performed well across the spectrum of predicted risk, but there was evidence of underestimation of mortality risk in neonates undergoing operation from 2007. CONCLUSIONS: The risk model performs well. Diagnostic information added useful discriminatory power. A future application is risk adjustment during routine monitoring of outcomes in the United Kingdom to assist quality assurance.

Use of diagnostic information submitted to the United Kingdom Central Cardiac Audit Database: development of categorisation and allocation algorithms.

OBJECTIVE: To categorise records according to primary cardiac diagnosis in the United Kingdom Central Cardiac Audit Database in order to add this information to a risk adjustment model for paediatric cardiac surgery. DESIGN: Codes from the International Paediatric Congenital Cardiac Code were mapped to recognisable primary cardiac diagnosis groupings, allocated using a hierarchy and less refined diagnosis groups, based on the number of functional ventricles and presence of aortic obstruction. SETTING: A National Clinical Audit Database. Patients Children undergoing cardiac interventions: the proportions for each diagnosis scheme are presented for 13,551 first patient surgical episodes since 2004. RESULTS: In Scheme 1, the most prevalent diagnoses nationally were ventricular septal defect (13%), patent ductus arteriosus (10.4%), and tetralogy of Fallot (9.5%). In Scheme 2, the prevalence of a biventricular heart without aortic obstruction was 64.2% and with aortic obstruction was 14.1%; the prevalence of a functionally univentricular heart without aortic obstruction was 4.3% and with aortic obstruction was 4.7%; the prevalence of unknown (ambiguous) number of ventricles was 8.4%; and the prevalence of acquired heart disease only was 2.2%. Diagnostic groups added to procedural information: of the 17% of all operations classed as "not a specific procedure", 97.1% had a diagnosis identified in Scheme 1 and 97.2% in Scheme 2. CONCLUSIONS: Diagnostic information adds to surgical procedural data when the complexity of case mix is analysed in a national database. These diagnostic categorisation schemes may be used for future investigation of the frequency of conditions and evaluation of long-term outcome over a series of procedures.

A method for early evaluation of a recently introduced technology by deriving a comparative group from existing clinical data: a case study in external support of the Marfan aortic root.

OBJECTIVE: During the early phase of evaluation of a new intervention, data exist for present practice. The authors propose a method of constructing a fair comparator group using these data. In this case study, the authors use the example of external aortic root support, a novel alternative to aortic root replacement. DESIGN: A matched comparison group, of similar age, aortic size and aortic valve function to those having the novel intervention, was constructed, by minimization, from among patients having conventional aortic root replacement in other hospitals during the same time frame. SETTING: Three cardiac surgical units in England. PATIENTS: The first 20 patients, aged 16-58 years with aortic root diameters of 40-54 mm, having external support surgery were compared with 20 patients, aged 18-63 years and aortic root diameters of 38-58 mm, who had conventional aortic root replacement, between May 2004 and December 2009. INTERVENTIONS: A pliant external mesh sleeve, customised by computer-aided design, encloses the whole of the ascending aorta. The comparator group had conventional aortic root replacement, 16 valve-sparing and four with composite valved grafts. MAIN OUTCOME MEASURES: Duration of cardiopulmonary bypass (CPB), myocardial ischaemic time, blood loss and transfusion of blood, platelets and clotting factors. RESULTS: Comparing total root replacement and customised aortic root support surgery: CPB (median (range)) was 134 (52-316) versus 0 (0-20) min; myocardial ischaemia 114 (41-250) versus 0 (0-0) min; 4 h blood loss was 218 (85-735) versus 50 (25-400) ml; and 9/18 had blood transfusion, 9/18 platelets and 12/18 fresh frozen plasma after root replacement versus 1/20, 0/20 and 0/20, respectively, for the novel surgery. CONCLUSIONS: Avoidance or large reductions in CPB, myocardial ischaemia and blood product usage were achieved with the novel surgery. These data are of use in decision analysis and health economic evaluation and are available early in evaluation before randomised trial data are available.